Please read the below thread about Fowl Pox:
This disease is a pain in the neck for many poultry farmers. It is the most prevalent disease in farmers keeping both the indigenous and exotic chicken breeds. The loss can be devastating if it comes in full force. Cutaneous avian pox(dry pox) is the ailment caused by an avian pox virus. Can be transmitted through mosquito bites and poor biosecurity. It is a viral disease and there is no cure for it.It is always wise to vaccinate for fowl pox twice in fowlpox endemic areas that are at 3 weeks and repeat at 6 weeks. Supportive treatment can be attempted(no actual treatment)to prevent secondary bacterial infections. Look for an antiseptic cream such as cetrino and apply on the affected areas. Combine it with a mild antibiotic in drinking water for 5 days.
PREVENTION AND CONTROL
-Control mosquitoes around poultry house by clearing the bush and draining stagnant water.
-Prompt vaccination of the flock against fowl pox. Done twice in fowlpox endemic areas at 3 weeks and at 6 weeks.
-Avoid introducing new birds into the flock without separating them.
Read more here:
https://mkulima.co/threads/fowl-pox.6378/